The last decade has seen significant research into robotic rehabilitation devices, primarily due to the significant patient populations and the associated costs of care. For example, 610,000 people in the U.S. experience a first-time stroke annually. The total cost of care, including direct and indirect costs, associated with the stroke population in the U.S. in 2010 was estimated at $53.9 billion. While not all these costs are due to an impaired gait, a significant percentage of stroke survivors have mobility impairments that affect their quality of life. For ischemic strokes, which represent 83% of all strokes, survivors face significant lasting impairments: six months after discharge, 50% exhibited hemiparesis, 30% required assistance to walk, 26% were in nursing homes, and 26% were in assisted-living centers.
A number of treadmill-based robotic rehabilitation devices have been developed to assist with the gait rehabilitation process for these patients with an impaired gait. Some of these have even emerged as commercial devices that are deployed in rehabilitation facilities. The current commercial leader in robotic-assisted gait rehabilitation is the LOKOMAT, developed by Hocoma. This device is a stationary Body Weight Support Treadmill (BWST) system with actuated hips and knees in the sagittal plane, as well as actuated forward/back pelvis motion. The system, which is large and stationary, is currently in use in a few large research hospitals across the country that can afford to purchase the device and sacrifice the space to house it. LOKOMAT researchers have put significant effort into making up for the biofeedback to the user that is lost by not walking in the real world by creating simulated environments and presenting feedback scores to the user. Other research efforts into similar technologies have sought to further extend the point to which the user imitates overground walking. One device is LOPES from the University of Twente, which includes full pelvic positioning in the forward/back and right/left directions as seen in overground walking. Another is ALEX from the University of Delaware that completely frees one leg of the user to better simulate overground walking for subjects with single leg impairments, such as stroke patients.
These systems have numerous drawbacks however. Nearly all approaches to date have been stationary devices where body weight is supported by a frame, and a treadmill device simulates overground motion. Motion of the treadmill forces lower extremity motion, even if the patient is trying not to move. The walking motion promoted by such systems bears only superficial resemblance to walking motion required in the real world. The patient is thus forced to further learn a different set of skills and abilities to operate in the normal real world environment after therapy with one of the stationary systems.
The invention addresses the need for a system which can provide therapeutic assistance that facilitates development of the muscular and neurological capabilities necessary for subsequent unassisted coping with real-world situations, and overcomes the shortcomings of the previous approaches.